This invention generally relates to an improved damper bush for radial shock absorption, and more specifically to an improved eye-bush for preferable use with an automobile multileaf spring which may offer an optimum spring characteristic under a wide range of shock loads radially applied thereto.
Generally, it has hitherto been difficult to provide a shock load or energy absorber of the type which has a satisfactory characteristic capable of absorbing impulsive energies effectively over a wide load range. To describe it in more details with reference to an eye-bush for use with an automobile multileaf spring, the problem lies in that for the purpose of merely eliminating or absorbing unobjectionable fine vibrations occurring under comparatively small load conditions, the damping eye-bush need only exhibit a comparatively low spring constant; but such a low spring constant of the eye-bush will result in a greater radial deflection of the bush under larger load conditions, thus causing problems of deteriorating its strength. On the contrary, if the eye-bush is given a higher spring constant, then the result will be that under smaller loads rather violent transmission of fine vibrations will occur and cause discomfort to a passenger aboard the vehicle where the eye-bush is mounted.
The present invention solves such prior art problems of the damper eye-bush relating to vibrations, durabilities, wheel-alignment variations, etc. by providing a novel eye-bush construction having a spring characteristic which within a range of smaller loads exhibits a lower rate of spring constant while exhibiting a higher rate of spring constant within a range of larger loads.